The use of countershaft transmissions having synchronizers for connecting various ratio gears to their respective shafts and then engaging a rotating fluid-operated clutch is well known. These transmissions are commonly termed "preselected dual clutch transmissions." Generally, these transmissions incorporate two selectively engageable fluid operated clutches and power operated synchronizers. These transmissions require bearing members to provide radial and thrust support of the various gear elements. The input clutches in a dual input clutch preselected type transmission are provided on the input axis. The clutches, therefore, rotate at the input, or engine, speed. Thus, the spin losses, in the open running clutch, can be quite high. The power transmission from the input shaft to the countershafts is generally provided at the same ratio.
One or more of the power shafts will generally require internal bearing supports. That is the shaft must be supported at a bulkhead which is secured in the transmission case. This complicates the assembly of these transmissions. When bulkheads are not used, all of the shafts extend the full length of the transmission and bearing support provisions must be made in the transmission case and end cover. A further disadvantage of these transmissions is found in that all of the gear members disposed on respective countershafts will rotate whenever the shaft is transmitting power.